duhvoodooman
Addicted to solder....
My souped up modification of the BYOC TS-808 clone pedal, which I call the "Zonkin' Yellow Screamer" (ZYS) has three switchable clipping modes. On the pedal, they're labeled Hot, Normal and Cool. The Normal mode uses the same basic silicon diode clipping as the original Tube Screamer, albeit set up asymetrically for a bit more smoothness. The Hot mode uses a pair of yellow LED's that give a louder, sharper overdrive that is often described as "Marshall-like" in its character. For the Cool mode, I've used a 3x3 array of 1N34A germanium diodes, which give a smoother, quite "bluesy" signal clip. While the tone is quite nice, the drawback to this mode is a significant loss in volume vs. the "dry" signal, due to the low voltage threshold of this diode type.
Through my reading on a number of different effects-related websites, I came across many references to other means of inducing signal clipping beyond simple diode arrays. One that caught my attention was MOSFET-based clipping (metal oxide semiconductor field effects transistor). MOSFET clipping is reputed to give a smoother overdrive tone than silicon diodes, similar to the germanium tone, but with more volume and fullness. The use of MOSFETs for clipping has become quite popular in high-end overdrive and distortion pedals--the Fulltone OCD and Fulldrive 2 pedals maybe the most familiar examples.
Anyway, since the parts involved were cheap--a couple of IRF520 MOSFET's at about a buck each, and a couple of 25 cent 1N34A germanium diodes--I decided to give it a try. I bought the MOSFETs from Small Bear Electronics, and soldered them and the 1N34A diodes (which I had a few of on hand) together on a small piece of perfboard. Then I just opened up my ZYS, removed the old 3x3 germanium clipping section, and wired in the new MOSFET array. While not as neat and well laid out as it would be if I'd built the pedal this way originally, it fits in the enclosure nicely and, most importantly, works perfectly.
The MOSFET clipping array does indeed give a very nice overdriven tone, and I can understand why they are popular in boutique pedals. While not quite as "soft" in character as the germanium array I used previously, it is very noticeably smoother and warmer sounding than the stock silicon diode clipping. It seems to have a somewhat fuller sound, too, which I would guess has something to do with harmonics. I'd say that this clipping mode comes as close to the tone of an overdriven tube amp as any pedal I've played personally. And the volume is essentially identical to the stock TS clipping, so no volume loss anymore when I switch to the Cool setting!
I'll try to get a clip posted in the next couple of days so that those interested can hear the difference for themselves....
Through my reading on a number of different effects-related websites, I came across many references to other means of inducing signal clipping beyond simple diode arrays. One that caught my attention was MOSFET-based clipping (metal oxide semiconductor field effects transistor). MOSFET clipping is reputed to give a smoother overdrive tone than silicon diodes, similar to the germanium tone, but with more volume and fullness. The use of MOSFETs for clipping has become quite popular in high-end overdrive and distortion pedals--the Fulltone OCD and Fulldrive 2 pedals maybe the most familiar examples.
Anyway, since the parts involved were cheap--a couple of IRF520 MOSFET's at about a buck each, and a couple of 25 cent 1N34A germanium diodes--I decided to give it a try. I bought the MOSFETs from Small Bear Electronics, and soldered them and the 1N34A diodes (which I had a few of on hand) together on a small piece of perfboard. Then I just opened up my ZYS, removed the old 3x3 germanium clipping section, and wired in the new MOSFET array. While not as neat and well laid out as it would be if I'd built the pedal this way originally, it fits in the enclosure nicely and, most importantly, works perfectly.
The MOSFET clipping array does indeed give a very nice overdriven tone, and I can understand why they are popular in boutique pedals. While not quite as "soft" in character as the germanium array I used previously, it is very noticeably smoother and warmer sounding than the stock silicon diode clipping. It seems to have a somewhat fuller sound, too, which I would guess has something to do with harmonics. I'd say that this clipping mode comes as close to the tone of an overdriven tube amp as any pedal I've played personally. And the volume is essentially identical to the stock TS clipping, so no volume loss anymore when I switch to the Cool setting!
I'll try to get a clip posted in the next couple of days so that those interested can hear the difference for themselves....
:thwap:
